Harmonic oscillation generating system



June 5, 1951 J DELVALIX 2,555,960

HARMONIC OSCILLATION GENERATING SYSTEM Filed Feb. 19. 1948 g. OUTPUT Z lnverwtor: Jean L. Deivaux,

H is Atto r'ney.

Patented June 5, 1951 HARMONIC OSCILLATION GENERATING SYSTEM Jean L. Delvaux, Asm'eres, France, assignor to General Electric Company, a corporation of New York Application February 19, 1948, Serial No. 9,363 In France October 16, 1945 Section 1, Public Law 690, August 8, 1946 Patent expires October 16, 1965 4 Claims. (Cl. 25036) My invention relates to an oscillation generating system of the type in which one or more harmonically-related frequencies are derived from a fundamental frequency.

Circuits embodying my invention are particularly adapted to use a duplex electron discharge device of known triode-hexode type, or similar type. Such a tube comprises within a common envelope a triode section and a multi-grid section which may be of the pentode, hexode, heptode, type etc., having at least two grid electrodes each capable of acting independently on the electron stream in the multi-grid section. In a conventional circuit utilizing a triodehexode, for example, the triode section is commonly included in an oscillator circuit and the hexode section is included in a modulator and mixer circuit. The control grid of the triode section is, in general, connected directly through a pressed on another control grid in a multi-grid section, which may hereafter conveniently be termed the signal grid.

In accordance with the principles of the present invention, means are provided for deriving from a triode oscillator circuit a harmonic voltage whose frequency is an integral multiple of the fundamental oscillator frequency. This harmonic frequency is then applied to the signal grid of the multi-grid section where it beats against the fundamental frequency supplied directly to the modulation grid. Finally, there may be selected in the output circuit of the multi-grid section one or more harmonic frequencies equal to the sum or difference frequency, and also the fundamental frequency if desired.

It is a principal object of the invention to provide an improved oscillation generating system for deriving from a primary source of oscillation frequency 1 one or more harmonically-- related frequencies of the form (nilh, where 11, is an integer.

It is another object of the invention to provide an improved oscillation generating system 'in which a plurality of harmonically-related frequencies may be generated and supplied from relatively simple circuits associated with a. single electron discharge device of the duplex type.

It is more specifically an object of the present invention to provide a simple and inexpensive oscillation generating system capable of providing a fundamental frequency f and a plurality of harmonically-related frequencies of the form (22111) where .n is an integer, this system comprising circuits associated with only a single tube of the triode-hexode type, or similar type.

For additional objects and advantages, and for a better understanding of the invention, attention is now directed to the following description and accompanying drawings, and also to the appended claims in which the features of the invention believed to be novel are particularly pointed out.

In the drawings:

Fig. 1 is a circuit diagram of one form of oscillation generating system embodying the invention; and

Figs. 2 and 3 are circuit diagrams of modified embodiments of the invention.

Corresponding elements in the several figures of the drawing have been designated by cor responding reference numerals.

Referring now particularly to Fig. 1, there is represented a system employing a known form of duplex tube I0 having a left-hand triode section [0a and a right-hand hexode section lflb. The electron streams in the two sections are electrically independent, and it will be understood that separate tubes might be utilized, although the construction illustrated is generally preferable for reasons of convenience, cost and physical size.

The triode section Illa comprises a cathode ll, control grid l2 and anode [3. These are connected in a suitable oscillation generating circuit. As represented, this circuit comprises a piezo-electric crystal element It connected between anode !3 and grid I2 and a resistor 15 connected between grid l2 and cathode Ii. Anode operating potential is supplied from any suitable B+ source, represented conventionally by battery l6 through conductor ll, a resonant circuit l8 and a resistor [9. The cathodes of both sections of device l0 are returned to the grounded negative terminal of the supply source 16 through a conventional resistance-capacitance network 20 which serves to provide an operating bias for certain electrodes of section [0b. In accordance with known practice, the crystal M maybe shunted by a capacitor 23, the resistor cuit I8 is tuned to an even. harmonic. fr,e.quency, which may be represented as, 21lf ,'[because the.

even harmonics in the anode circuit of the oscillator section will in general be more intensive than the odd harmonics.

The multi-grid section illb of Zn comprises acathode 30, a plurality of grids 3 I-3,4 and an;

anode 35. The first or signal grid 3,|;is;arrangedto have harmonic frequency voltage impressed thereon by means of a winding 36 coupledto the resonant circuit IS. The third or modulation grid. 33; has oscillations of the fundamental-oscillator frequencyimpressed, thereon. by, reason of the. direct internal; connection. 35!; between grid 33-; and the triode grid; i-2.. Suitable-operating essentials are; impressed upon the second and, fourth; grids Rand; 3' 1 conventional man: nor from supply source; it, through a filter nete work. comprising a resistor 38 and by-passicapacitor 4.3;. Anode, 35: is also. connected to the positive terminal. f; supply source l-fithrough a pair of resonant circuits 39 and 40 in seriesand conductor H;

Assuming. that a fundamental frequency f is impressed on modulation grid 33. and an even harmonic frequency- 2.n-f is. impressed; upon-.- signal grid3l, the circuits 39- and 40- may be tuned to; select the sum; and differences frequencies (2n+1)f and (Zn-1) respectively. These two frequencies may be supplied to suitable output circuits (not shown) by means of the. coils 4i and 42 coupled to the resonant circuits 39 and 40, respectively.

The amplitudes of the harmonic. frequencies supplied to the output; circuit may beadjusted by adjusting the impedanceof the. self-bias network 28. in a cathode return circuitof section b. It will of course beapparent. that-,the frequencies may also be stabilized in conventional manner by thermostatic control of the.- temper.- ature of crystal M, and if necessary by, thermostatic control of the other frequency-determine ing elements of the system.

Fig. 2; represents a. modified; embodimenthf the invention which-operates.insubstantially the same manner as that-of Fig, l'but which differs in that the tuned circuit I8, is connected; in shunt to the anode circuit of sectiomlila through a coupling capacitor 5t, instead.- of. being connested in series with the anodesuppl-y'circuit as in the case of Fig. 1.

It will also be apparent that, other formseof oscillator circuits known to the art may-be. em.

ployed. In some cases it may beidesirable. to supply oscillations of the fundamentalfrequency f-to the control grid i2; from; an externalioscillation generator. A circuit arrangement of. this latter type is represented i-nF-ig, 5'. Thiscircuit differs from that of Fig 21in that, the funda: mental frequency, oscillationsr are supplied from any suitable external source 5t and. impressed upon control grid: t2 through. a. coupling-- ca.- p ni en i- While certain specific-1embodiments have; been shown and described; it will, ofcourse; be'underr stood; that. various other modifications may;- be

made without departing from the invention. The appended claims are therefore intended to cover any such modifications within the true spirit and? scopeof the invention.

What lclai'm as new and desire to secure by Letters Patent of the United Statesis:

1. An oscillation generating system comprising a. first electron. discharge path including an anode, cathode and control grid, means for impressing oscillations of fundamental frequency f on". said control. grid, a resonant Circuit connected between said anode and cathode tuned to a harmonic frequency 11, where n is an integer, a. second electron discharge path including'ananode, cathode and a plurality of grid electrodes, means comprising a direct connection fromsaid control grid to one of said' grid electrodes for impressing frequency f thereon, means-coupling said resonant circuit to another of said grid electrodes to impress frequency nf thereon, and.- an; output circuit connected between the; anode and:- cathode' of. said second device; tuned toselect acbeatfrequency from the group consisting of (n+1); and- (Yb-1H.

2;. An oscillation generating system. comprising, a first electron discharge path including an anode, cathode; and. control. grid, an oscillator circuit including said path and operating at. a fundamentahfrequency 7, a resonant. circuitconnested. between said anode and. cathode timed to. an even. harmonic frequency 2'nf, where 11 is aninteger, a second electron. discharge. path including an. anode, cathode. and, a plurality of grid electrodes, means comprising, a direct con,- nection from said control grid to. one of" said gridelectrodes for impressing frequency fthereonjrom said oscillator. circuit, means coupling said resonant circuit" to another of said'grid electrodes to impress frequency Znfthe'reomand an output circuit connected between the anode and cathode of's'aidsecond-devicetuned to-select abeat frequency from the group cons-isting 'of (n+1) fand'in-l") 7:

3'. An oscillation generating systenrcomprising, a duplex electron discharge device having a triode section and amulti-gr-id section within a commontube envelope;- a direct connection from the grid-ofsaid'triode --section-ito one:grid of" said multi-grid section, an oscillator-circuit including said triode section and. operating; at a fundamental frequency I,.. an. resonant. .ciricllit excited by said oscillator. circuit. and; tuned-.to an' even harmonic frequency. 2.1113: wheregn: 15.3.11 integer, meansfor. impressing; said. harmonic frequency on another. grid: of said multiegrid section, and an output; circuit; including: said multi-grid section and; comprising..a..tuned oil..- cuit. resonant:at..a.-beainfrequency;from thocsrolip consisting. of: (n+1). is and; (n'. ),;f:.

4. oscillationgenerating. system; comprise ing a duplex. electron discharge device; having triode and-multiegrid sections withima common tube envelope, said: multi-grid. sectiorn including a...mcdulationz.gridi and a. signal grid a. direct connection between the gridofzsaidtrioide sec? tion, and. said; modulation grid,., an oscillator circuit; including. said triode: section and; oper..- ating to impress a, fundamental frcgaeney, f; on said; directlyrconnected grids, a.-resonant circuit excited by. said oscillator circuit and tuned to an even harmonic frequency 2-nf, Where. 1S1. an.

integer, means for impressing said harmonic frequency, on saidsignaligrid, and-amanode out.- niit circuit forsaid. multi-grid section. including two; resonant circuits; one.- tuned totselect. the

2,555,960 5 difference frequency (Zn-1) f and the other tuned to select the sum frequency (2n+1)j.

Number 1,559,116 JEAN L. DELVAUX. 2,191,903 5 2,241,933 REFERENCES CITED The fol lowmg references are of record In the Number file of thls patent: 544 959 6 UNITED STATES PATENTS Name Date Marrison 1 Oct. 27, 1.925 Aldous Feb. 27, 1940 Roberts May 13, 1941 FOREIGN PATENTS Country Date Great Britain May 5, 1942 

